1. Field of the Invention
the present invention relates to techniques for processing a substrate coated with a resist film and processed by an exposure process for development by a developing process.
2. Background of the Invention
A photoresist pattern forming process, namely, one of semiconductor device fabricating processes, forms a resist film on a surface of a semiconductor wafer (hereinafter, referred to simply as “wafer”), exposes the resist film to light in a predetermined pattern, and then develops the exposed resist film by a developing process using a developer to form a resist pattern. A known developing process mentioned in JP-A 2006-60084 holds a wafer by a spin chuck, namely, a substrate holding device, spouts a developer onto the wafer through a developer spouting nozzle moving from a position above the circumference of the wafer toward a position above the center of the wafer while the wafer is rotated about a vertical axis.
A known exposure system processes a wafer by an immersion exposure process which form a liquid film, such as a pure water film, over the wafer to attain high exposure resolution. Studies have been made to make the immersion exposure process achieve a throughput equal to that of the conventional exposure system by improving the follow-up scanning performance of an immersed part of the exposure system, namely, the tip of the lens, by forming a highly water repellent protective film on a resist film or by forming a highly water repellent resist film. The water repellency of those films has been progressively improved. However, the high water repellency of the surface of the wafer enhances difficulty in uniformly spreading a developer over the surface of the wafer in a developing process. Consequently, it is possible that the degree of defective development increases with the further minimization of the minimum feature size of patterns.
Developing methods mentioned in JP-A 2006-60084 and JP-A 2002-75854 coat a rotating wafer with a developer by rotating the wafer in one direction and then rotating the wafer in the opposite direction while the developer is being continuously spouted onto the wafer. If the surface of the wafer has high water repellency, it is difficult to spread the developer uniformly particularly in a circumferential part of the surface and the above-mentioned problems cannot be solved.